This is the Long Cage Version of the SRAM Force 1 Rear Derailleur for 1x road drivetrains. The SRAM Force 1 Rear Derailleur adopts all the technologies of SRAM 1x MTB to provide the fastest, quietest 1x11 shifting available. SRAM’s unique clutch system eliminates chain slack, providing for smoother, quieter, and more secure chain travel.